Data analysis
munication function had been evaluated. In particular, parents
were requested to evaluate whether AAC use had resulted in
improvement of communication function equalling a shift in
level within the CFCS, compared with when AAC was not used.
The study was pre-approved by the Stockholm Regional
Ethical Review Board (No. 2013/544-31/2).
Young adults with cerebral palsy
169
Swedish legislation prohibits access to patient charts
without consent, thus making analysis of non-partici-
pants restricted to age (no difference) and sex, with the
proportion of women among non-participants (n = 42,
33%) not statistically different from the participants.
Data were analysed in Stata IC 14 for Mac. Descriptive data
are presented as frequency and proportion or median and range
as appropriate. The descriptive data are presented for the total
sample, as well as grouped by level within the GMFCS, MACS,
CFCS, and by presence of intellectual disability. The subgrou-
ping was done to increase interpretability of the results given
the large variation of disability in CP. The 5 levels within the
GMFCS, MACS and CFCS were dichotomized as levels I–II
or levels III–V, to enable clinically meaningful presentation
given the sample size.
In the analysis of associations, the outcomes of particular
interest were further grouped into binary yes/no categories, as
“moved away from parental home”, “experience of intimate
relationships”, “in regular employment or attending higher edu-
cation”’, “independent personal finances”, and, as the question
on friendships that appeared most reliable during data collection;
“socializes with friends, outside home, including on evenings”.
These binary yes/no items were analysed for associations with
the GMFCS, MACS, CFCS (dichotomized as previously des-
cribed) and presence of intellectual disability, with crude odds
ratios calculated from 2 × 2 tables. Adjusted odds ratios were
obtained by controlling for the presence of intellectual disability
on each association separately, using logistic regression model-
ling (Stata IC 14).
The findings of the added data collection on communication
function were prepared descriptively.
There were no missing data due to the data gathering ap-
proach used.
RESULTS
Recruitment process
Sixty-one young adults, i.e. 44% of those who could be
reached, and 32% of the entire target study population
consented to participate (Fig. 1). There was no prior
data collection on the target study population, and
Recruitment process
Born 1992–1995 and having an ICD-10
diagnosis of cerebral palsy (CP)
n=208
Target study population
n=139
n=189
Contacted
n=138
Exclusion, and reason
n=4, deceased
n=1, emigrated
n=3, protected/unknown address
n=11, erroneous ICD-10 code (not CP)
n=51, unable to reach (see Methods)
n=77, declined to participate
Study participants
n=61
n=61
Fig. 1. Flow-chart illustrating the recruitment of study participants.
CP: cerebral palsy; ICD-10: International Statistical Classification of
Diseases and Related Health Problems Tenth Revision.
Fig. 2. (a) Distribution of levels within the classification systems for the
study sample of young adults. GMFCS: I (n = 25, 41%), II (n = 8, 13%),
III (n = 7, 12%), IV (n = 9, 15%), V (n = 12, 20%). MACS: I (n = 13, 22%),
II (n = 24, 41%), III (n = 4, 7%), IV (n = 4, 7%), V (n = 13, 22%). CFCS:
I (n = 33, 54%), II (n = 5, 8%), III (n = 6, 10%), IV (n = 10, 16%), V
(n = 7, 12%). (b) Distribution of clinical subtypes of cerebral palsy (CP)
in the study sample. Bilateral spastic CP (n = 29, 48%). Unilateral spastic
CP (n = 22, 36%). Dyskinetic CP (n = 7, 11%) Atactic CP (n = 2, 3%).
Unclassifiable CP (n = 1, 2%). (c) Distribution of intellectual disability (ID)
within subgroups of the classification systems. GMFCS: levels I–II (21%),
levels III–V (75%). MACS: levels I–II (21%), levels III–V (91%). CFCS:
levels I–II (13%), CFCS III–V (100%). CP: cerebral palsy; GMFCS: Gross
Motor Function Classification System; MACS: Manual Ability Classification
System; CFCS: Communication Function Classification System; ID:
intellectual disability.
J Rehabil Med 51, 2019